part of part of in taxon Vertebrata <vertebrates> embryonic structure germ ring ZFA:0000111 TAO:0000111 EFO:0003427 The thickend rim of the blastoderm evident during late blastula and gastrula stages[FishBase]. Embryonic structure which is a uniform thickened annulus at the blastoderm margin, consisting of two layers in addition to the EVL, the epiblast and the hypoblast. The germ ring is formed by the involution of the blastoderm back upon itself[ZFA]. AAO:0000211 MAT:0000255 UBERON:0002541 MIAA:0000255 gastrula